Various types of touch panels that simultaneously detect a touch position when an operator touches a planar operation surface with his/her finger or the like and a pressing amount upon the touch have conventionally been proposed. For example, Japanese Unexamined Patent Publication No. 05-61592 (Patent Document 1) describes a touch input device having a structure in which a flat-plate pressure sensor and a touch panel detecting a touch position are superimposed in close contact with each other. This touch input device detects a touch position with the touch panel. On the other hand, a pressing amount is detected by the pressure sensor that is formed separate from the touch panel and superimposed on the touch panel.
Patent Document 1: Japanese Unexamined Patent Publication No. 05-61592